Will 15 Celsisus Temp Kill My Danios?

I live in Mexico and I hate heaters, lol. For once they sound expensive, and I am also afraid my heater will explode killing all the fish (very unlikely to happen but who knows...)
I wanted to keep Goldfish (no heater required) but I would need a 100lt tank to keep 2 (I could keep one but I would feel bad for him, I want him to have a mate) and right now I think my parents would kill me if I bought a 100lt tank so I am thinking of something smaller.

I was thinking about putting some Danios with some Amano Shrimp in a 60~ lt tank (around 15 gals), but I'm afraid I need a heater.
I tested water temps in a 1lt bottle and the lowest temperature I recorded was of 15 Celsisus (59 Farenheit) in the winter. The temperature is usually at between 20-25 Celsius (68-77 Farenheit), and I guess temperature wouldnt drop as low when it commes to a bigger mass of water.

Still, I am wondering if my Danios risk dying in winter when the temperature at night drops to 15 Celsius at worst, what do you guys think? Should I get White minnows instead? I like Danios much more, but I would preffer to keep live minnows than dead danios.

Also, could some of you tell me how much kilowatts per hour your heater consumes? Anyone knows how much kilowatts would a heater for a 60 lt tank consume? If it is low enough I may be able to use a heater which would open the doors for good looking tropical fish like guppies.
Thanks in advance.

 

I live in Mexico and I hate heaters, lol. For once they sound expensive, and I am also afraid my heater will explode killing all the fish (very unlikely to happen but who knows...)
I wanted to keep Goldfish (no heater required) but I would need a 100lt tank to keep 2 (I could keep one but I would feel bad for him, I want him to have a mate) and right now I think my parents would kill me if I bought a 100lt tank so I am thinking of something smaller.

I was thinking about putting some Danios with some Amano Shrimp in a 60~ lt tank (around 15 gals), but I'm afraid I need a heater.
I tested water temps in a 1lt bottle and the lowest temperature I recorded was of 15 Celsisus (59 Farenheit) in the winter. The temperature is usually at between 20-25 Celsius (68-77 Farenheit), and I guess temperature wouldnt drop as low when it commes to a bigger mass of water.

Still, I am wondering if my Danios risk dying in winter when the temperature at night drops to 15 Celsius at worst, what do you guys think? Should I get White minnows instead? I like Danios much more, but I would preffer to keep live minnows than dead danios.

Also, could some of you tell me how much kilowatts per hour your heater consumes? Anyone knows how much kilowatts would a heater for a 60 lt tank consume? If it is low enough I may be able to use a heater which would open the doors for good looking tropical fish like guppies.
Thanks in advance.

They are very hardy fish, but 15 degrees Celsius is below the minimum threshold for Zebra Danio's. The recommended low range is 17.78-18.33 Celsius. You would be putting them in stressful environment. You must also consider at lower temps their apatite and metabolism will decrease. I'd go with another species that can tolerate lower temps.

 

Thanks for the info!
Yeah, 3 degress lower than something already low looks like bullying.
If I buy them I will probably get a heater and just turn it at night so their temperature doesn't go as low as 15 celsius.
I know lower temps reduce their apetite and metabolism, but I don't like keeping fish at constant temperatures, in the nature their temperatures go lower at night, altho not to 15 celsius, I checked the weather for Vietnam and it usually stays at 18-20 celsius at night

 

Thanks for the info!
Yeah, 3 degress lower than something already low looks like bullying.
If I buy them I will probably get a heater and just turn it at night so their temperature doesn't go as low as 15 celsius.
I know lower temps reduce their apetite and metabolism, but I don't like keeping fish at constant temperatures, in the nature their temperatures go lower at night, altho not to 15 celsius, I checked the weather for Vietnam and it usually stays at 18-20 celsius at night

The problem with that is that these fish are captive bred, and have grown up in waters of constant temperatures
Also, the air outside would stay at pretty much a constant temperature, while your tank would continue to get lower due to ambient room temp being different.
My tank was at 23 degrees, and without a heater for dropped to 17. It's not safe for fish, and unsteady and constant changes in temp like that can stress them out. If you get a good heater you will not have to worry about it exploding, especially if you buy a shatterproof one (I believe Marineland make one). They aren't massively expensive either, and the only time you have to worry about them exploding or breaking is leaving them on and exposing them to air.

I have the same fear, but I have trust in my equipment. And I know if something happens, I'll do my best to fix it. Aquarium equipment will fail one day from being on constantly, but they are meant to last a very very long time. If you really don't want a heater, try a colder fish.

 

Thanks, I have thought about it and I'm gonna get some cloud minnows, I thought they were ugly but they arent! Their red is great, and they are cold-resistant. Now I just need to book up on quarantine...
I am thinking of getting Cherry Shrimp too, I red they can withstand temperatures up to 14 Celsius.

Regarding temperature shocks, the water starts losing about 1 degree Celsius per hour around 7:00 PM, I don't think that is enough to shock them, what do you think?

 

White clouds have a pretty good temperature range, and are often used in outdoor ponds

I'm no professional, but I would guess that an indoor tank would not experience temperature swings of a drastic nature, because we would use some means of warming the environment for our own comfort

Our comfort zone of 20-25 is just fine for wcmm.

My heater is by jäger, and was well priced. It can be set to anywhere from 65-90farenheight I have a 100w for a 29 gallon tank

Heaters like that only come on if your tank drops below the temperature that you set, so if you had a heater in a wcmm tank, set for 21degrees, it would likely only ever come on at night or in winter. Neon tetras do well with wcmm, and they like it at only 23degrees stable

I'm not sure what your tank size is in gallons though, and they need a 20 gallon minimum with heater

 

I'm anti-heater, I'm scared the bills will go high and my parents will kill me lol, so I don't think I will keep Tetras or any tropical fish anytime soon, unless until I get a job and go nuts with this fishkeeping stuff.
I'm planning on getting a 10-15 gal tank and putting around 7 WCMM with some RCS (is that how you abreviate Red Cherry Shrimp?) to have kind of a clean up crew but must importantly to have some action at the bottom.
The only means of warming ourselves here in Mexico are sweaters , but as I said, I already tested the water temp in some 1lt bottles and the water swings were not that drastic (1 Celsius per hour or so), just a normal day-night shift.

 

I have a night-day shift here as well and here's what I have observed

The wcmm pale out at the lower temperature(19-20)and find shelter. They like a glass bottle cave and hornwort(a plant which will thrive in cold water)

When temperature is about 22, they colour up and become active, darting around the tank and seeking food

You can always throw a blanket over the tank at night to reduce temperature drops, fish like a well established night-cycle so the dark won't bother them

I can't speak on the shrimp because I have only had ghost shrimp in my cold water tanks

 

Thanks for all the comments and help guys. I thought about life and finally got into this hobby. Here is what I got:
1- 10 Gal tank (I thought my furniture could hold 15 gal tanks but it couldnt so I had to buy a base and mess up with my budget...)
2- Cascade Filter that pumps 300 liters per hour. I think that is pretty good filtration plus my LFS gifted me some cycled media and told me how to modify the filter so it filters the most. (I filled half of it with the cycled media he gave me and the other half with a thick sponge for the physical filtration. It also works to grow bacteria tho. So the filter system rocks!) I also love the cascade, creates a nice current and helps oxygenate the water.
3- Heater. I realized I couldnt live without a heater, so I bought an automatic one. I keep the water temperature at 24 Celsius (75 Farenheit).
4- I also got some decor for the fish, some shells and a little ceramic container. (The typical egipt-looking one...)

As for Stocking:
This is my ultimate goal:
3-4 Mollies.
7 Dwarf Corydoras
Right now I currently have 2 Mollies and 5 Dwarf Corydoras, I'm slowly increasing the fish each weekend I go to the fish store to keep it slow without risk of overflowing the system and killing all my fish...
In case there is discussion about mollies needing 20 gal tanks... My Local Fish Store guy with 35 years on the hobby told them it was OK to keep them in 10 gal tanks and approved my overall stocking. As for the mollies, they seem super happy, they are swimming around, picking at the gravel, picking at the plants (He gifted me an Amazonas Sword and I bought a clove looking plant. )etc... This is getting addictive tho so maybe if I get a half-time job I will upgrade the tank to a 30 gal tank in the future.

 

I'd be inclined to hold at 5-6 cories, as the tank is small....you can always add more if you upgrade.

It's my experience that a ten gallon becomes difficult to maintain the more fish you keep in it, and you want the mollies too..even one less fish can help when managing bioload

The filter sounds great and it's awesome that you were able to get a jump start on your cycle.

With the temperature range of your heater, you can pick nearly any plant you like, which is again awesome. I have found that hornwort grows great in 75degrees, and wisteria too. Java fern will do well as well

The sword will get big, so you will probably want it in the middle of the tank or something